1. Field
The following description relates to a toner for developing an electrostatic charge image and a method of manufacturing the same.
2. Description of Related Art
Methods of visualizing image information by utilizing electrostatic charge are currently used in various fields. An example of such a method is an electrophotographic method in which, after uniformly charging a photoreceptor surface, an electrostatic charge image is formed on the photoreceptor surface, and then an electrostatic latent image is developed by using a developer. The developer may include a toner, and the developed image is referred to a toner image. This toner image is transferred and fused to a recording medium to form a stable image. As the developer, a two-component developer that includes a toner and a carrier may be used. In the alternative, a one-component developer that includes a magnetic toner or a non-magnetic toner alone may be used. In recent years, to reduce power consumption and to save energy, the toner image is often fused at a low temperature. To fuse the toner image at the low temperature, a method for lowering a glass transition temperature of a binder resin of the toner may be used. Also, according to a method of manufacturing a toner, a kneading and grinding method in which a thermoplastic resin is melt-kneaded together with colorants such as a pigment, charge control agents, and release agents such as a wax, and is milled and classified after cooling, may be used. However, in a common kneading and grinding method, a toner shape and a toner surface structure are irregular. As a result, a reliability deterioration such as display quality deterioration due to a charge deterioration of the developer, toner scattering, and developing property deterioration is caused. Accordingly, in recent years, a method of manufacturing the toner by an emulsion polymerization aggregation method capable of intensively controlling the toner shape and the toner surface structure has been proposed. JP Patent Publication Nos. 1988-282752 and 1994-250439 discuss examples of toner manufacturing methods. According to a toner manufacturing method, at least a resin particulate dispersion solution manufactured by the emulsion polymerization and a colorant particle dispersion solution in which the colorant is dispersed in the solvent are mixed, and an aggregation material corresponding to a toner particle size is formed. Next, the aggregation material is heated to be fused and coalesced, and a toner particle of a desired particle size is obtained. According to this manufacturing method, a small particle size of the toner particle is not only facilitated, but also an excellent toner is obtained in a particle distribution. As the binder resin of the toner, a polyester resin having an excellent fixability and permanence has been generally used. In general, it is necessary to synthesis the polyester resin at a high temperature of more than 200° C., and recently, from a point of view of reducing an environmental impact, to reduce energy consumed in the toner manufacture process, polymerization of the polyester resin at a low temperature has been studied.